Place the pine nuts in a dry frying pan large enough to hold them in a single layer. Dry means you don't need to add oil or water to the pan.
Turn the heat to medium-low and toast the pine nuts until fragrant and golden brown, stirring frequently or even constantly, especially as they begin to brown.
When they're golden brown, immediately transfer them from the hot skillet to a plate to stop the cooking and prevent scorching. Nuts should be in a single layer to cool.
Microwave Method:
Spread pine nuts in a single layer on a microwave-safe plate. Microwave on full power (100%) for 1 minute, stir, and then continue to microwave in 30 second intervals, stirring each time, until golden brown.
Keep an eye on them, especially towards the end, because they can burn quickly. The microwave tends to heat unevenly so some nuts may be untoasted while others scorch if you're not watching and stirring every 30 seconds.
Transfer to another plate to cool; arrange in a single layer.
Oven Method (or toaster oven):
Preheat oven to 375ºF.
Spread pine nuts in a single layer on a rimmed baking sheet.
Bake for 5 to 10 minutes, stirring every 2 to 3 minutes, or until golden brown.
Immediately transfer to a plate to cool, in a single layer. Don't leave them in the hot pan because they will continue to brown.
Video
Notes
You can easily toast more than a ½ cup of pine nuts. If you toast more than 1 cup at a time, the oven method works best.
Store both raw and toasted pine nuts in either the refrigerator or freezer to keep them from becoming rancid.
All 3 methods can be used to toast other types of nuts and seeds, too.